Method of and means for utilizing the heat in furnaces of the channel type.



No. 876,712. PATENTED JAN. 14, 1908.

G. GRONDAL. METHOD OF AND MEANS FOR UTILIZING THE HEAT IN FURNACES OF THE CHANNEL TYPE. APPLICATION FILED 001214, 1905.

10 SHEETS-SHEET 1.

WITNES/SES INVENTOR AT OR N E YS PATENTEDJAN. 14, 1908. G. GRONDAL.

METHOD OF AND MEANS FOR UTILIZING THE HEAT IN FURNACES OF THE CHANNEL TYPE. APPLICATION FILED 00114, 1905.

WITNEQSEQ m/ww 10 SHEETS-SHEET 2.

INVENTOR k/g iwm ATTORNEYS PATENTED JAN. 14, 1908. G. GRONDAL. METHOD OF AND MEANS FOR UTILIZING THE HEAT IN FURNACES OF THE CHANNEL TYPE.

APPLICATION FILED OOT.14, 1905.

10 SHEETSSHEET .3.

m T u N E V m ATTORNEYS PATENTED JAN. 14, 1908. G. GRONDAL.

IN FURNACES 10 sinus-SHEET 4.

ON @N INVENTOR WITNES ES f ATTORNEYS No. 876,712. PATENTED JAN. 14, 1908.

- G. GRONDAL. METHOD OF AND MEANS FOR UTILIZING THE E EAT IN FURNACES OF THE CHANNEL TYPE. APPLICATION FILED 001 14, 1905.

10 SHEETS-SHEET 6.

m T N u E V m ATTOR NEYs No. 876,712. PATENTED JAN. 14, 1908.

G. GRONDAL.

METHOD OF AND MEANS FOR UTILIZING THE HEAT IN FURNACES OF THE CHANNEL TYPE. APPLIOATION FILED 001'. 14, 1905.

1o SHEETS-SHEET 6 INVENTOR WITNESSES [q 2 FrMd A'FTOR N EYS PATENTED JAN.14, 1908. G. GRONDAL. METHOD OF AND MEANS FOR. UTILIZING THE HEAT IN FURNACES OF THE CHANNEL TYPE. APPLICATION FILED 001?. 14, 1905. v

10 SHEETS-SHEET 7.

INVENTOR ATTORNEYS aw H H W H H H T s WITNESSES No. 876,712. I'PATENTED JANP14, 1908.

G. GRONDAL.

METHOD OF AND MEANS FOR UTILIZING THE HEAT IN FURNACES OF THE CHANNEL TYPE.

APPLICATION FILED 00114 1905. I

' 1o SHEETS-SHEET 8.

SECTI-ON EF.

WI NE SE5 5 Wfm ATTORNEYS No. 876,712. PATENTED JAN.14, 1908. G. GRONDAL. METHOD OF AND MEANS FOR UTILIZING THE HEAT IN FURNACES OF THE CHANNEL TYPE.

APPLICATION FILED 00T.14, 1905.

10 SHEETS-SHEET 9.

SECT/ON L-M. 55c T/ON /v-o.

INVENTOR WITNESSES SEC'TIIQN P-Q.

ATTORNEYS PATENTED JAN. 14, 1908.

' G. GRONDAL. METHOD OF AND MEANS FOR UTILIZING THE HEAT IN F URNA CBS OF THE CHANNEL TYPE. APPLICATION FILED 001. 14, 1905. 10 SHEETS SHEET 1.

INVENTOR SEC'T/ION v x ATTORNEYS UNITED STATES PATENT OFFICE.

GUSTAF .GRONDAL, OF DJURSHOLM SWEDEN,.ASSIGNOR TO METALLURGISIIA AKTIE- BOLAGET, OF STOGKHOLM, SWEDEN, A CORPORATION OF SWEDEN.

METHOD OF AND MEANS FOR. UTILIZING THE HEAT IN FURNACES F TEEGIIANNEL TYPE.

To all whom it may concem: T

-Be it known. that I, GUsTAF GRoNnAL, a

furnaces of the kind-that comprises a prefliminary heating compartment and a cooling compartment and a-burning or baking chamber situated between these compartments and intowhich burning or baking chamber thefuel is fed and in which chamber it is' consumed, and the goods or articles being placed on movable supports are passed through the furnace intermittingly. The invention is characterized. thereby that a larger quantlty of air than necessary for the complete combustion of the fuel is fed into the furnace at the delivery end and that the amount of the air not necessary for the combustion, beingheated by contact with the burned goods or articles in the cooling compartment, is conducted past. the burning chamber and introduced again into the furnace at a point in the preliminaryheating compartment where the temperature of the combustion products 1 from .the burning chamber is practically equal to the temperature of the air reintroduced.

.. .intothe furnace- This air mingles with the combustion products and transmits its heat to the goods 'or articles in the preliminary heating compartment, thereby increasing their temperature. A large quantity of air may also be fed beneath the heated supports, carrying the burned goods or articles,

and

desired tern erature. This air is thereby heated and 1s afterwards led 'into the pre liminary heating compartment in order also to utilize this heat, which is transmitted to the goods in the preliminary heating compartment.

In the accompanying drawings there is represented, by wayjofan example-only, a continuously working channelfurnace w th gas firing particularly intended for burning f ore briquets, and. provided with the fea- .-tures necessary for executing the purposes of the invention.

Figures 1 and 2 represent the' complete Specification of Letters Patent. Application filed October 14. 1905b. Serial No. 282.765-

the. supports be cooled downtoany' furnace in a side view and from above. Flg s. 3-19 are views of the furnace on a larger scale with parts broken awayto save Patented Jan. 14, 1908'. g

room' on the drawings. FigsM3, 4 and 5 represent the greater part of the preliminary heating compartment: of the' furnace respectivelyin a side vi'ew and in a vertical longitudinai section through the center of the furnace and in a horizontal section on line A..B of Figs. 3 and 4. Figs. 6, 7'and 8 represent respectively the corres onding view and sectlons ofparts of. the urning chamber and cooling compartments: Figs. 9 to 18 are cross sections throu h the furnace onlines-CD, EF, GH, K, LM, NO, PQ, R S, TU, and VX respectively-of Figs. 1,4 and 7. Fig. 19 is an end view of the delivery end of the furnace.

For facilitating the draft the furnace is built sloping upwards towards thechimney.

The furnace is provided with rails 1, 1 slightly inclined in the same direction, '11. e.

from the inlet endtowards the deliveryend' for facilitating the forward movement of the loaded trucks along the furnace. 2-, 2 are troughs along bothsidesof the furnace, in-

tended to be filled with sand. The trucks,

one of which is indicated by 3 in Figs. 7 and 18, have" the end faces of their bottoms of a suitable form to make a practically tight '-joint between two trucks standing end to end, and they are provided at their sides with iron plateswhich project into the sand troughs 2. By means ofthe tightly closing bottoms of the trucks and the sand traps the furnace thus' becomes divided in two separate chambers one above the other,

chamber proper, and the lower one 5, the channel under the bottoms of thetrucks through which a portion of the air is led.

This channel 5 communicates through a transverse channel 6 with an air inlet namely the upper chamber 4, the furnace feed air'to several furnaces, if desired. The i channel 5 communicates at the end with the furnace chamber 4 by means of side-channels 1-1, 11, which open through the holes 12, 12. In the channels 11, 11 there ar provided regulating dampers 13, 13.

14 is a tube or main conduit supplying'the 35 pers in the-channels 28.

- The ends of the furnace are closed by ducer.

combustible gas, for instance from a gas pro- From, this tube 14 issues a branch 15 that leads to the furnace and opens through an oblong aperture 16 in the roof of the furnace, that is somewhat higher at this point. Behind this aperture 16 an arch 17 ,of the cross section shown in Fig. 7.

leading into a discharge conduit 19 forthe" superfluous air. This conduit 19 opens into i for such furnaces.

'two' channels 20 extending along the furnace, whichend in a transverse, channel 2L communicating with the furnace chamber 4 by means of openings 22, Fig. 4, in the roof .of the'fur'nace. Under this opening 22 a portion 23-of the vault of the furnace projects in the manner shown for facilitating the mixture of the air with'the combustion products The 1 coming from the burning chamber. channels 20 are provided with dampers 24: capable .of being operated from the outside of the furnace. 25, Fig. 7, is a valve casing for a valve (not shown) between the gastube 14 and the conduit 15. 26, 26 arecleaning doors. 26 is-thedoor for tending;

a fire when necessary..'

At the inlet end of the furnace or at'the front end of the preliminary heating com-- partment there is provided a discharge passage 27 in the roof of the furnace. This discharge 27 communicates by means of chan-- 1 nels 28, Fig.-9,-.with t,he hue 29 leading tothe chimney. 30, 30

doors 31 capable of being raised andilowered. 32,. li'igs. 4 and 5, is a railroad on which the loaded truck is carried to the furnace 'on a carriage 33 provided with rails track-in the furnace. 35, Fig. 5, is a dynamo driving by means of belt36 and gear-= 1 ing a conveyer 37 by which the loaded truck is pushed into the furnace and pushes: j the whole line of trucks in the furnace for- Y ward directly after a truck-has been removed from the cooling compartment. I

The furnace operates 111 the manner known in similar furnaces, and the heat then ab sorbed by this portion of the air is delivered hitherto.

compartment which thereby become heated are regulating dam mg from the invention. For instance the By being able to force j I a larger supply of air into the cooling coml partment than is required for the combus'= tion ofthe fuel the burned goodsare cooled -more effectively than could be done hitherto in the cooling and heating compartments of the furnace and after being heated is intro- .duced into the preliminary heatmgcompartment.

When. introducing a loaded truck into the furnace at the end for the preliminary heating, thereby pushing the hne of trucks as a whole towards the end for the cooling so that one truck is expelled there and removed, the first truck of the line remaining in'the furnace should have the position occupied by the truck 3 in Fig. 7 or thereabout. It is thereby rendered possible that a portion of the air from the fan 7 passes by the foreend of this truck and rises up into the furnace chamber 4 While another portion of the air passes through the channel 5. A By means of the dampers 13, 13, Fig. 12, the air may be distributed at will in the two chambers 4 and 5. By means of the dampers 24, 24., Fig. 13, it may be determined how large a portion of the air is to be led past the combustion place and how large a portion of the air is to be led into the combustion place. pressure reigns in the two chambers 4 and 5,

In normal working an equal along said chambers have no tendency to pass over from the channel 5 to the chamber 4 or the converse. 4 In starting the furnace a fire may be hghted at the gas inlet through the door 26", Fig. 7. As mentioned above, the furnace as shown on the drawings only serves as an example and the dimensions anddetail maybe varied according to circumstances without departfan' may be dispensed with and only the draft through the chimney employed.

1. Method of. utilizing the heat in furnaces having a preliminary heating compartment,

a coohng compartment and an intermediate burning chamber,,in which latter the fuel is fed and burned, and throughwhich compartments and chamber the goods or articlesare fed intermittently, said method consisting in feeding air over the goods in the cooling compartment to, and using it for combustion in the burning chamber, said air being in larger quantity than is necessary for the combus tion of the fuel required for producing the necessary heat in the burning chamber, and leading the superfluous quantity of air heated inithe cooling compartment past the burning chamber and introducing it together with the products of combustion from the burning chamber into the preliminary heating coml j partment to there ,deliver its heat to the to the goods, in the preliminary heating,"

goods.

2. A channel furnace with gas firing for burning ore briquets and the like, consisting of a preliminary heating compartment, a coohng compartment and an intermediate burning chamber, in which latter the fuel is fed and burned, and trucks. passing through said compartments and chamber and on which the goods or articles are placed, means for introducing air through the cooling chamber into the burning chamber, and in larger quantities than is necessary for use in the burning chamber, and said furnace being pro vided with a controllable conduit for that portion of the air not necessary for the comustion of the gas, the said conduit being made to issue from the cooling compartment and being led past the burning chamber and opening at a suitable point into the preliminary heating compartment of the furnace together with a controllable conduit leading from the furnace and o ening into thepre liminary heating channe whereby the products of combustion mingle with the surplus air from the cooling chamber to effect the preliminary heating desired.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses.

GUSTAF GRONDAL. Witnesses:

FREDRIK L. EN UIsT, HJ. FETTURSTRGM. 

